/*=============================================================================*
 *  Copyright 2004 The Apache Software Foundation
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *=============================================================================*/
package topics;


/**
 * Interface that should be implemented by parties interested in changes in topics and the list of root topics. It is
 * currently used to send notifications when the situation represented by a topic changes and for tracking the list of
 * currently supported topics (exposed as a resource property)
 */
public interface TopicListener
{
   /**
    * Called when the value of the topic changes
    *
    * @param topic The topic that changed
    */
   void topicChanged( Topic topic );
}